Tektronix TCP0150, Instruction Manual

Page: 37 / 102

Application Examples
High-Impedance Pulse Sources
If the pulse source has a higher impedance of
known resistance, such that the output voltage
drops as the current increases, the inductance
of a coil can be calculated by the time constant
of the charge curve.
The current ramp shows how the values for the
inductance formula are obtained.
Use this formula to calculate the inductance
based on the current measurement:
where:
L is the inductance in henries,
τ is the time required for the current to rise
or fall 63.2% of the total current value, and
R is the source resistance of the pulse
generator.
TCP0150 Current Probe Instruction Manual 21